Hi!
On May 12, 2009, at 11:14 AM, Sergei Golubchik wrote:
> - init() function. Brian added that to pass handlerton down.
> it is ignored by any clean plugin API and should've been done
> differently for storage engines and I_S tables.
You should take a look at what Drizzle does as an example:
static int compressionudf_plugin_init(PluginRegistry ®istry)
{
registry.add(&compressudf);
registry.add(&uncompressudf);
registry.add(&uncompressed_lengthudf);
return 0;
}
If I remember correctly the void * was used because before the
solution you had devised required that every time we updated a
structure we had to update every single plugin (and the original
pointer change was done by Tomas Ulin, not myself).
> - MYSQL_THD is defined as void*, which is fine as it's an opaque
> pointer, plugins are never expected to look inside to cast it to
> anything.
write_row() in the handler is another example of exposing vs
encapsulation (which is fine... if you want to go with C over C++).
>> Without doing this, and using encapsulation so that a THD can have
>> multiple
>> Statements, it will be very difficult to work on any future
>> parallelization
>> efforts.
>
> You mean, a Statement can have multiple THDs, I suppose :)
No he means what he is saying. I don't know why you would want a
statement shared across multiple THD, but having a THD be able to
handle multiple statements means that you can do asynchronous queries
within a single connection.
Cheers,
-Brian
